Use a union to cast int to fp

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5849 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2003-04-22 20:20:28 +00:00
parent 8829dcd15b
commit 7a5a1f790f

View File

@ -73,15 +73,17 @@ static uint64_t HexIntToVal(const char *Buffer) {
// point representation of it.
//
static double HexToFP(const char *Buffer) {
uint64_t Result = HexIntToVal(Buffer);
assert(sizeof(double) == sizeof(Result) &&
"Data sizes incompatible on this target!");
// Behave nicely in the face of C TBAA rules... see:
// http://www.nullstone.com/htmls/category/aliastyp.htm
//
char *ProxyPointer = (char*)&Result;
return *(double*)ProxyPointer; // Cast Hex constant to double
union {
uint64_t UI;
double FP;
} UIntToFP;
UIntToFP.UI = HexIntToVal(Buffer);
assert(sizeof(double) == sizeof(uint64_t) &&
"Data sizes incompatible on this target!");
return UIntToFP.FP; // Cast Hex constant to double
}